This project is an offspring of the studies with EOE-13. The same experimental contrast material is used, Ethiodized Oil Emulsion 13 (EOE-13). We hypothesized that by fractionating the administration of this contrast material, we are able to deliver a larger intravenous dose and obtain a denser liver and spleen without increasing the untoward side effects. Since biodistribution studies with EOE-13 have shown that the clearance of this contrast material from the blood is rather rapid, we felt that after a 30-60 minute period, the second follow-up dose would be well-tolerated and deposited in the liver and spleen. Since the clearance of the contrast material from the liver and spleen is minimal in the first hour, this additional dose of contrast material would mostly add to the density of liver and spleen, without appreciably increasing the iodine level of the blood and other body organs. Methods Employed: The study will be performed on 6 average-sized male or female Rhesus monkeys. Following laparotomy, preliminary liver biopsy and blood sample will be obtained. An IV infusion of 0.3 ml per kilogram EOE-13 will follow this, with 15-minute infusion time. Blood samples at 5, 30, and 60 minutes following the completion of the infusion will be obtained. The liver biopsies will be repeated at 5 and 60 minutes following the first injection. Sixty minutes following the completion of the first EOE-13 infusion, a second infusion will be started with the same dose of the contrast material and the same infusion time. Blood samples will be obtained, as after the first infusion, and a single liver biopsy will be performed at 5 minutes following completion of the second infusion. The iodine concentration of the obtained blood samples and liver.